Method for molding finger rings

ABSTRACT

A method of molding a finger ring having a hollowed out interior portion which includes forming a ring pattern by forming a first structure of a first moldable material in the shape of the final ring, dissolving a layer of desired thickness from such first structure, to form a second structure, forming a third structure by introducing a second moldable material into a cavity between the second structure and a molding apparatus, forming a fourth structure by dissolving all of said first material from said third structure, forming a fifth structure by introducing a third moldable material into a cavity between the fourth structure and an arbor, and finally, introducing a fourth moldable material into a cavity between the fifth structure and a molding apparatus.

United States Patent [191' Voegele [451 Oct. 1, 1974 METHOD FOR MOLDINGFINGER RINGS [75] Inventor: Lawrence R. Voegele, Owatonna,

Minn.

[73] Assignee: Jostens, Inc., Owatonna,.Minn.

[22] Filed: June 1, 1973 [21] Appl. No.: 366,025

[52] US. Cl 164/45, 249/57, 264/221, 264/227 [51] Int. Cl. B22c 7/02[58] Field of Search 164/45; 249/57; 264/221, 264/227 [56] ReferencesCited UNITED STATES PATENTS 3,302,257 2/1967 Kaplan 249/57 X 3,511,4665/1970 Kaplan 249/57 3,601,178 8/1971 Marticorena 164/45 3,678,9877/1972 Kydd 164/45 3,720,397 3/1973 Voegele 249/57 PrimaryExaminer-Robert D. Baldwin Assistant Examiner-John E. Roethel Attorney,Agent, or Firm-Dorsey, Marguart, Windhorst, West & I-lalladay [5 7]ABSTRACT A method of molding a finger ring having a hollowed outinterior portion which includes forming a ring pattern by forming afirst structure of a first moldable material in the shape of the finalring, dissolving a layer of desired thickness from such first structure,to form a second structure, fonning a third structure by introducing asecond moldable material into a cavity between the second structure anda molding apparatus, forming a fourth structure by dissolving all ofsaid first material from said third structure, forming a fifth structure'by introducing a third moldable material into a cavity between thefourth structure and an arbor, and finally, introducing a fourthmoldable material into a cavity between the fifth structure and amolding apparatus.

10 Claims, 6 Drawing Figures METHOD FOR MOLDING FINGER RINGS BACKGROUNDOF THE INVENTION The present invention relates generally toa method ofmolding finger rings, and more specifically, to a method of moldingfinger rings having a hollowed out or recessed interior portion and amethod of making the ring pattern for use in molding such finger rings.

Normally, scholastic rings such as those purchased by students asgraduation and class rings, are molded from a relatively precious metalsuch as gold or silver. Such rings are molded throughout from thisprecious metal including the entire interior protion of the ring betweenthe exterior surface thereof and the cylindrical bore which contacts thefingerof the wearer. These rings are relatively expensive due, in part,to the great amount of precious metal which is used in molding the ring.Further, such rings are quite heavy and retard the ability of thewearers finger to breathe during use because of the presence of thismetal in the interior portion of the ring. Consequently, it is desirablein terms of reducing the cost and weight of such rings and providingcomfort to the wearer to eliminate a portion of the precious metal whichis used in the formation of these rings. One portion which is desirableto eliminate is that portion which exists between the exterior: surfaceof the ring and the portion which contacts the finger of the wearer.This portion of the ring performs little, if any, function and does notcontribute to the external appearance of the ring. By reducing oreliminating the material which is molded in this portion of the ring,the cost of such a ring can be reduced substantially. It is desirable,however, for the hollowed out portion or the portion which is eliminatedto substantially conform in all details to the exterior surface of thering to enable the final molded ring to have a relatively uniformthickness throughout and to maximize the amount of material which can beeliminated. Although efforts have been made to mold rings with such ahollowed out interior portion, such methods have been unsatisfactoryboth from a cost standpoint and in terms of the quality of the hollowedout portion. One such method involved forming a ring pattern in aconventional manner and then hollowing out the interior portionmanually. This method, however, required substantial expense because ofthe labor required to perform such hollowing out, and resulted in a ringpattern which did have a uniform thickness. Consequently, there is areal need in the finger ring molding field for an improved method bywhich finger rings may be molded with a hollowed out interior portion.

SUMMARY OF THE INVENTION ln contrast to the prior art, the presentinvention relates to a method of molding a finger ring having a hollowedout interior portion wherein the accomplishment of such method isrelatively inexpensive and wherein the hollowed out portion conformssubstantially, ex-

cept in smaller dimensions, to the details of the exterior uble in afirst solution. After the wax material has sufficiently hardened. themold structure is separated and the cylindrical arbor with the ringshaped wax structure mounted thereon is exposed to the first solutionfor a specified period of time in order to dissolve a layer of wax ofdesired thickness from the surface of such structure. Then, thispartially dissolved wax model which is still mounted on the arbor isplaced back into the mold structure and a second wax material which isnonsoluble in said first solution is introduced into the cavity formedbetween the exterior surface of the first wax model and the interiormolding surface of the molding structure. When this has hardenedsufficiently, the mold structure is again separated, the arbor removedfrom the resulting wax structure and the wax structure exposed to thefirst solution until the first wax portion of this structure hascompletely dissolved. The resulting structure, which is then composedentirely of the second wax material, is placed back onto the arbor andbetween the molding structures. A plastic molding material is thenintroduced into the cavity formed between the cylindrical arbor and theinterior surface of the second wax material model and allowed to harden.After sufficient hardening, the resulting structure is removed from themolding structure and the exterior second wax portion is removed fromthe molded plastic portion which is molded to the arbor. This arbor,with the plastic portion now securely molded thereto, constitutes thefinal molding arbor for use in the ring molding method of the presentinvention. Finally, this molding arbor is placed between the moldingstructure and the ring is molded with a conventional process such as thelost wax or investment method of casting.

Accordingly, it is an object of the present invention to provide amethod of molding a finger ring of the type having a hollowed outportion between the exterior surface of the ring and the finger of thewearer.

Another object of the present invention is to provide a relativelyinexpensive method for molding a finger ring having a hollowed outportion wherein the hollowed out portion of said finger ring conformssubstantially, in all details, to the exterior surface of the ring.

Another object of the present invention is to provide a method formolding a finger ring with a hollowed out portion wherein such fingerring has a relatively uniform thickness throughout.

Another object of the present invention is to provide a method formolding a finger ring with a hollowed out portion which includes amethod of making a finger ring mold for the molding of such finger ring.

These and other objects of the present invention will become apparentwith reference to the drawings, the description of the preferred methodand embodiment for performing such method and the appended claims.

DESCRIPTION OF THE DRAWINGS FIG. 4 is a view, partially in section, ofthe third intermediate mold structure which is formed during the ringmolding process of the present invention.

FIG. 5 is a perspective view of an intermediate mold structure which isformed during the molding process of the present invention.

FIG. 6 is a perspective view of the final finger ring which has beenformed and molded via the method of the present invention.

- DESCRIPTION OF THE PREFERRED METHOD AND EMBODIMENT FOR PERFORMING SUCHMETHOD Reference is first made to FIG. I which illustrates an expandedview of the molding apparatus which is intended to be used in theperformance of the molding method of the present invention. The moldingapparatus of FIG. 1 includes a pair of molding members 11 and 12, a pairof backing members 16 and 18 associated with the molding members 1 l and12 respectively, a mandrel or arbor 19, and a plug 20. When combinedtogether in their normal operative relationship, the pair of moldingmembers 11 and 12, the arbor 19,-and the plug 20 form a first moldingcavity into which a moldable material may be introduced to produce apattern for the molding of an article such as a finger ring.

More specifically, each of the molding members 11 and 12 includes aflat, smooth surface area comprised of the surfaces 14,.14a and 14b andsurfaces 15, a and 1512 respectively, which are designed for cooperativeengagement when the molding members 11 and 12 are placed together in anoperative position. Each of the surfaces 14a and 14b includes analignment tab 21 adapted for correspondence with an alignment recess 22located on each of the surfaces 15a and 15b. When the surfaces 14a and14b are placed in contact with the surface 15a and 15b, the tabs 21engage the recesses 22 to properly align the molding members 1 1 and 12.Each of the molding members 11 and 12 further includes, respectively, asemi-annular beveled surface 24 and 25 for cooperation with a beveledsurface 26 of the plug and a semi-cylindrical interior surface 28 and 29for engagement with the relatively cylindrical arbor 19.

The portions of the members 11 and 12, the plug 20 and the arbor 19which actually contact the moldable material and form the first moldingcavity include the surfaces 32 and 34 of the members 11 and 12respectively, the surface 33 of the plug 20 and the exterior cylindricalsurface of the arbor 19. A sprue hole 35 is in communication with thisfirst molding cavity and serves as a means for introducing the moldablematerial into such molding cavity.

The mandrel or arbor 19 is a relatively cylindrical member which, in thepreferred embodiment, is composed of a plastic material. The arbor 19 isintended to engage the semi-cylindrical surfaces 28 and 29 of, and bedisposed between, the molding members 11 and 12. It should be noted thatalthough the arbor 19 is shown as a single cylindrical member, it iscontemplated that a pair of half arbors could be used in its place. Asillustrated, the arbor 19 includes a pair of holes 36 extendingtherethrough for cooperation with a pair of alignment pins 38 which arealso intended to extend into the holes 39 and 40 in the backing members16 and 18 respectively to properly align the molding members 11 and I2and the arbor 19.

Having now described the molding structure intended to be used inperforming the method of the present invention, such method will now bedescribed as follows: First, with reference to FIG. 1, the moldingmembers 11 and 12, the arbor l9 and the plug 20 are placed together inan operative relationship so that a first molding cavity'is formedbetween such members. Then, a first moldable material which is solublein a first solution is injected through the sprue hole 35 into the firstmolding cavity. In the preferred method, the first solution is water andthe first moldable material is a water soluble wax which may beidentified as No. 700 Light Green Water Soluble Wax manufactured byCasting Supply Company of New York, NY. Although it is contemplated thata variety of different types of waxes and materials may be used as thefirst moldable material, such material must be capable of dissolvinguniformly from its surface when exposed to the solvent in which it issoluble. Further, the wax must be such that it does not soften whenexposed to such solution. In the preferred method, the above identifiedfirst material was selected because it dissolved uniformly from itssurface and because it met the other characteristics referred to above.Following the introduction of the water soluble wax into the firstmolding cavity, the wax therein is allowed to harden. After sufficienthardening, the mold sections 11 and 12 are separated from each other andthe arbor 19 with the water soluble wax molded thereto is removed. Thisresulting structure, which shall hereinafter be referred to as the firstintermediate mold structure, is similar to that which is illustrated inFIG. 2. With reference to FIG. 2, it can be seen that the firstintermediate mold structure includes the arbor l9 and a water solublewax ring model 41 molded thereto. The ring model 41 has an exteriorappearance similar to that of the final ring product which isillustrated in FIG. 6. Extending downwardly from the model 41 is a sprue42 which is formed during the molding process as a result of theintroduction of water soluble material into the sprue hole 35 (FIG. 1).

Following removal of the first intermediate mold structure from the moldsections 11 and 12, it is immersed in water of approximately Fahrenheit.As soon as this structure is immersed into the water, the ring portion41 and the sprue 42 which are composed of a water soluble wax begin todissolve. Such dissolving is allowed to continue until the ring 41 andsprue 42 (FIG. 2) has been reduced to the desired size. It should benoted that during the dissolving process referred to above, only theportion of the ring 41 and the sprue 42 which is not in contact with thearbor I9 is dissolved, thus, the interior portion of the ring 41 whichis in engagement with the exterior cylindrical surface of the arbor 19is not affected by the water. After the desired dissolving has takenplace, the arbor 19 with the ring structure 41 and sprue 42 mountedthereon is removed from the water and dried. In the preferred method,the desired dissolving has occurred when the diameter of the sprue 42has been reduced by 0.050 inches. This means that a layer 0.025 inchesthick will have been dissolved from the entire surface of the ring model41.After completion of the dissolving step, the resulting structure,which shall hereinafter be referred to as the second intermediate moldstructure, is illustrated in FIG. 3. As shown, the ring which is nowidentified by reference numeral 44 is reduced in size by approximately0.025 inches over its entire surface and the sprue, now identified byreference numeral 45, is reduced in diameter by 0.050 inches. Ifdesired, the edges of the ring 44 contacting the arbor 19 may be furthercut away or routed manually to provide sufficient surface contactbetween the final ring and the finger.

Next, the second intermediate mold structure illustrated in FIG. 3 isplaced between the molding sections 11 and 12 (FIG. 1) and the sections11 and 12 are clamped together in an operative position. When this isaccomplished, a molding cavity, which will hereinafter be referred to asthe second molding cavity, is formed between the surfaces 32 and 34 ofthe sections 11 and 12, the exterior surface of the ring 44 and sprue 45(FIG. 3), and a portion of the arbor 19. This second molding cavity willbe approximately 0.025 inches in thickness corresponding to thethickness of the layer which was dissolved during the dissolving stepdescribed above. A second moldable material is then introduced into thesecond molding cavity through the sprue hole 35 (FIG. 1) and allowed toharden. This second moldable material is a material which is nonsolublein the first solution referred to above. Because the first solution inthe preferred method is water, the second moldable material is amaterial which is not water soluble. More specifically, the secondmaterial is a non-water soluble wax which may be identified as H.P.granulated wax manufactured by Denton Precision Casting Supply Companyof Warwick, Rhode Island.

After the non-water soluble wax introduced into the second cavity hasbeen allowed to harden sufficiently, the mold sections 11 and 12 areseparated and the resulting structure and arbor 19 are removed. At thispoint, the resulting structure, which shall hereinafter be referred toas the third intermediate mold structure, is very similar in appearanceto that which is illustrated in FIG. 2, except that the structure has aportion composed of the first material (water soluble wax) and a portioncomposed of the second material (non-water soluble wax). As more clearlyillustrated in FIG. 4, which shows a cross sectional view of the thirdintermediate mold structure, the ring model, which is now identifiedgenerally by the reference numeral 46, includes an inner portion 48which is composed of a water soluble wax and an outer layer 49,approximately 0.025 inches in thickness, composed of a non-water solublewax material. Similarly, the sprue includes an inner portion 56 composedof the first material and an outer portion 55 composed of the secondmaterial. The ring model structure 46 is then removed from the arbor 19by cutting a portion of the ring band and peeling it off. The ring 46 isthen submerged in water of approximately 100 Fahrenheit until the watersoluble wax portion 48 has completely dissolved. In the preferred methodit has been determined that immersion of the ring 46 in 100 Fahrenheitwater for approximately minutes will dissolve the entire water solublewax portion 48. Following the dissolving of the portion 48, theremaining structure, which shall hereinafter be referred to as thefourth intermediate mold structure,'includes only the portion 49composed of a non-water soluble wax.

Following the dissolving of the portion 48 from the ring structure 46 ofFIG. 4, the portion 49 (fourth intermediate mold structure) and thearbor 19 are placed between the mold sections 11 and 12. The moldsections 11 and 12 are then placed together forming a mold cavity, whichwill hereinafter be referred to as the third molding cavity; between thearbor l9 and the inner surface of the ring portion 49 (FIG. 4). A thirdmoldable material is then poured into the third molding cavity through ahole (not shown) in the signet portion of the ring until the cavity isfilled. This material is then allowed to cure. The third material issuch that it bonds securely to the arbor 19 and, in the preferredmethod, is a plastic material which is known as L-l Castolitemanufactured by The Castolite Company of Woodstock, Ill. After the thirdmoldable material has sufficiently cured, the molding sections] 1 and 12are separated and the arbor l9 and resulting structure bonded thereto isremoved. At this point, the structure which shall hereinafter bereferred to as the fifth intermediate mold structure, is similar inappearance to that illustrated in FIG. 4, however, it is composed of anexterior layer of the non-water soluble wax and an interior portionshaped similar to the portion 48 of FIG. 4 but composed of the thirdmoldable plastic material. The exterior layer of non-water soluble waxis then peeled from the interior plastic portion and the resultingstructure is then similar to the structure illustrated in FIG. 3. Thesprue and a portion of the ring band are then manually removed from thefifth mold structure so that the final structure is similar to thatillustrated in FIG. 5. As shown, a part of the band portion 53 of thisstructure is cut away. This is done on the palm side area of the ring toallow for sufficient finger size adjustment.

With the use of the mold structure illustrated in FIG.

5, the ring pattern which is used in molding the final ring product maybe formed. To accomplish this, the structure which is illustrated inFIG. 5 is placed between the mold halves 11 and 12 (FIG. 1) and a ringpattern wax or fourth moldable material is introduced into the moldingcavity formed between the molding surfaces of the members 1 l and 12 andthe exterior surface of the structure illustrated in FIG. 5 through thesprue hole 35 (FIG. 1). When this wax has suff ciently hardened, themolding members 11 and 12 are separated and the resulting ring pattern(not shown) which now conforms substantially to the final ring productis removed from the arbor 19. The ring pattern is then used to form thefinal ring by a method which is known as the lost wax or investmentmethod of casting. To accomplish this, the ring pattern is encased in aninvestment plaster material until the plaster is hardened. Then, the waxmodel is vaporized by use of extreme heat in a burn out furnace therebyleaving a pattern chamber in the plaster mold. Molten metal of the typewhich is desired to be used in the final ring product is then introducedinto the pattern chamber and allowed to solidify. When sufficienthardening has taken place, the plaster is broken away leaving thesolidified ring. As illustrated in FIG. 6, a gem or stone 52 and bezel57 are then mounted to the ring 54 in a known manner. The

final ring 54 of FIG. 6-also includes a hollowed out interior portion 51which is formed in accordance with the method of the present invention.This hollowed out portion enables a ring such as that illustrated inFIG. 6 to be molded from substantially less material than the methods ofthe prior art. Further, the ring 54 is of relatively uniform thicknessthroughout as a result of for mation via the method of the presentinvention.

Although the description of the preferred method of the ring moldingmethod of the present invention has been quite specific, it iscontemplated that various changes and modifications could be madewithout deviating from the spirit of this invention. Thus, the scope ofthe present invention is intended to be measured by the appended claimsrather than by the description of the preferred method.

I claim:

1. A method of making a finger ring comprising the following methodsteps:

introducing a first moldable material which is soluble in a firstsolution into a first molding cavity formed by at least two moldingsections and an arbor to form a first structure;

exposing said first structure to said first solution to form a secondstructure;

introducing a second moldable material which is nonsoluble in said firstsolution into a second cavity formed between said molding sections andsaid second structure to form a third structure;

exposing said third structure to said first solution to form a fourthstructure; introducing a third moldable material into a third cavityformed between said fourth structure and said arbor to form a fifthstructure; and

introducing a fourth moldable material into a fourth cavity formedbetween said fifth structure and said molding sections.

2. The method of claim 1 including exposing said third structure to saidfirst solution until all of said first moldable material has dissolvedtherefrom.

3. The method of claim 1 wherein saidfirst solution is water, said firstmoldable material is a water soluble wax and said second moldablematerial is a non-water soluble wax.

4. The method of claim 1 wherein the introduction of said fourthmoldable material into said fourth cavity results in the formation of afinger ring pattern.

5. The method of claim 4 including encasing said finger ring pattern inan investment plaster material and molding a finger ring via theinvestment method of casting.

6. The method of claim 1 including exposing said first structure to saidfirst solution until a layer of desired thickness has been dissolvedfrom the surface of said first structure.

7. The method of claim 6 including exposing said first structure to saidfirst solution until a layer approximately 0.025 inches thick has beendissolved from the surface of said first structure.

8. The method of claim 1 wherein the step of forming said fifthstructure includes allowing said third moldable material to harden andremoving said fourth structure from the hardened third moldablematerial.

9. The method of claim 8 wherein said fifth structure includes a portionof said third moldable material securely bonded to said arbor.

10. A method of molding a finger ring which comprises the followingmethod steps:

forming a first structure by introducing a first moldable material whichis water soluble into a first molding cavity formed by at least twomolding sections and an arbor extending therebetween;

forming a second structure by removing the arbor with said firststructure molded thereto and exposing said first structure to water fora preselected time to dissolve away a layer of desired thickness fromthe surface of said first structure;

forming a third structure by placing said second structure and saidarbor between said molding sections and introducing a second moldablematerial which is non-soluble in water into a second molding cavityformed between the molding sections and the second structure;

forming a fourth structure by removing said third structure from saidmolding sections and said arbor and exposing said third intermediatemold structure to water until all of the first moldable material hasdissolved from said third structure;

forming a fifth structure by placing said fourth structure and saidarbor between said mold sections and introducing a third moldablematerial into a third molding cavity fonned between said fourthstructure;

forming a finger ring pattern by removing said fifth structure with saidarbor molded thereto from said molding sections and removing the secondmoldable niaterial therefrom and introducing a fourth moldable materialinto a fourth cavity formed between said fifth structure and the moldingsections.

forming a finger ring from said finger ring pattern via the investmentmethod of casting.

1. A method of making a finger ring comprising the following methodsteps: introducing a first moldable material which is soluble in a firstsolution into a first molding cavity formed by at least two moldingsections and an arbor to form a first structure; exposing said firststructure to said first solution to form a second structure; introducinga second moldable material which is non-soluble in said first solutioninto a second cavity formed between said molding sections and saidsecond structure to form a third structure; exposing said thirdstructure to said first solution to form a fourth structure; introducinga third moldable material into a third cavity formed between said fourthstructure and said arbor to form a fifth structure; and introducing afourth moldable material into a fourth cavity formed between said fifthstructure and said molding sections.
 2. The method of claim 1 includingexposing said third structure to said first solution until all of saidfirst moldable material has dissolved therefrom.
 3. The method of claim1 wherein said first solution is water, said first moldable material isa water soluble wax and said second moldable material is a non-watersoluble wax.
 4. The method of claim 1 wherein the introduction of saidfourth moldable material into said fourth cavity results in theformation of a finger ring pattern.
 5. The method of claim 4 includingencasing said finger ring pattern in an investment plaster material andmolding a finger ring via the investment method of casting.
 6. Themethod of claim 1 including exposing said first structure to said firstsolution until a layer of desired thickness has been dissolved from thesurface of said first structure.
 7. The method of claim 6 includingexposing said first structure to said first solution until a layerapproximately 0.025 inches thick has been dissolved from the surface ofsaid first structure.
 8. The method of claim 1 wherein the step offorming said fifth structure includes allowing said third moldablematerial to harden and removing said fourth structure from the hardenedthird moldable material.
 9. The method of claim 8 wherein said fifthstructure includes a portion of said third moldable material securelybonded to said arbor.
 10. A method of molding a finger ring whichcomprises the following method steps: forming a first structure byintroducing a first moldable material which is water soluble into afirst molding cavity formed by at least two molding sections and anarbor extending therebetween; forming a second structure by removing thearbor with said first structure molded thereto and exposing said firststructure to water for a preselected time to dissolve away a layer ofdesired thickness from the surface of said first structure; forming athird structure by placing said second structure and said arbor betweensaid molding sections and introducing a second moldable material whichis non-soluble in water into a second molding cavity formed between themolding sections and the second structure; forming a fourth structure byremoving said third structure from said molding sections and said arborand exposing said third intermediate mold structure to water until allof the first moldable material has dissolved from said third structure;forming a fifth structure by placing said fourth structure and saidarbor between said mold sections and introducing a third moldablematerial into a third molding cavity formed between said fourthstructure; forming a finger ring pattern by removing said fifthstructure with said arbor molded thereto from said molding sections andremoving the second moldable material therefrom and introducing a fourthmoldable material into a fourth cavity formed between said fifthstructure and the molding sections. forming a finger ring from saidfinger ring pattern via the investment method of casting.